The invention concerns a device for heating and/or air conditioning the passenger compartment of a motor vehicle, of the type comprising fan means able to send an air flow through a casing housing at least one heat exchanger and communicating with a deicing outlet, a ventilation outlet and a feet-level outlet.
Devices of this type are already known in which the casing houses an evaporator and a heating radiator so that an air flow can pass successively through the evaporator and heating radiator in order to be cooled and/or heated therein, according to the thermal air comfort desired by the occupant or occupants of the vehicle.
The air flow thus cooled and/or heated is then set to the different areas of the passenger compartment through the deicing outlet, the ventilation outlet and the feet-level outlet.
From EP-0 733 502, a device of this type is known comprising a double fan fed on the one hand by an external air flow taken outside the passenger compartment and on the other hand a recirculated air flow taken from inside the passenger compartment. This device thus makes it possible to treat the external air flow in order to send it into a region of the passenger compartment, for example at the upper part, and to treat the recirculated air flow in order to send it into a another region of the passenger compartment, for example in the lower part.
However, the performance of such a device is limited because it uses only a single fan and the operating modes are reduced. This is because this known device does not make it possible to effect a separate management between the two regions of the passenger compartment, namely the upper part and the lower part.
U.S. Pat. No. 4,842,047 concerns an air conditioning device which comprises two coaxial fans able to send air flows into two adjacent channels delimited by a separating partition.
This device does not make it possible to vary the proportion between the two air flows and, in addition, the coaxial arrangement of the two blowers limits the possibilities of locating these blowers.
U.S. Pat. No. 5,309,731 concerns a motor vehicle air conditioning device which comprises two air passage conduits each having a fan and a heat exchanger. The fan situated in a first conduit sucks in the recirculated air, heats it and then sends it into the motor vehicle passenger compartment through lower ventilation vents. The fan situated in the second conduit sucks in the external air, heats it and then sends it into the passenger compartment through deicing vents.
This device does not make it possible to vary the proportion of the air flows passing through the heat exchangers and coming from one and/or other of the fans. In addition, the management of the external air source and the management of the recirculated air source are dependent on each other.
The aim of the invention is notably to overcome the aforementioned drawbacks.
It aims principally to procure a device capable of generating two independent heat exchange flows, one intended for the upper part of the passenger compartment and the other for the lower part of the passenger compartment, in order notably to dispense with problems of misting of the vehicle windows.
To this end it proposes a heating and/or air conditioning device of the type defined in the introduction, in which the fan means comprise a first fan able to send a first air flow through a first part of a heating radiator and a second fan able to send a second air flow through a second part of this radiator, in which a distribution means is provided in the casing, upstream of the radiator with respect to the second air flow, in order to control the first air flow and/or the second air flow through the radiator, and in which distribution means are provided for distributing the first and second air flows, which have passed through the radiator, between the deicing outlet, the ventilation outlet and the feet-level outlet.
Thus the device of the invention comprises two fans able to generate two separate air flows intended to be sent into two parts of the passenger compartment, that is to say generally the upper part and the lower part.
Because of this, it is possible to distribute, to the upper and lower parts of the passenger compartment, two air flows treated independently for temperature.
The distribution means makes it possible to control, proportion and/or layer the first air flow and the second air flow which pass through the radiator. The result is a regulation of the proportion of the first air flow and of the second air flow, without mixing these two air flows. It is possible in some to cause either the first air flow alone or the second air flow alone to pass through the radiator.
In a preferred embodiment of the invention, an evaporator is interposed between the first fan and the radiator, so that the first air flow passes successively through the evaporator and the radiator, whilst the second air flow passes only through the radiator.
Thus the first air flow can be cooled and/or heated, whilst the second air flow can only be heated.
According to another characteristic of the invention, the first fan and the second fan are able to be fed each by an external air flow and/or a recirculated air flow.
Preferably, the first fan is able to be fed by an external air flow and/or a recirculated air flow, whilst the second fan is able to be fed by a recirculated air flow.
According to another characteristic of the invention, the first part of the radiator is at the top part and is situated on the same side as the deicing outlet and the ventilation outlet, whilst the second part of the radiator is at the bottom part and is situated on the same side as the feet-level outlet.
Preferentially, the deicing outlet and the ventilation outlet can be fed by an air flow which has passed through the evaporator (where applicable) and the radiator, whilst the feet-level outlet is fed by an air flow which is passed through the second part of the radiator, without having passed through the evaporator.
In one embodiment of the invention, the first fan and the second fan are both disposed on the same side, or upstream side, of the radiator, whilst the deicing, ventilation and feet-level outlets communicate with an outlet chamber situated on the opposite side, or downstream side, of the radiator, so that the first air flow and the second air flow pass through the radiator in the same direction.
In this embodiment, the outlet chamber advantageously houses a distribution shutter able to adopt at least two different positions: a closed position in which the outlet chamber is divided into a first compartment and a second compartment so that the first air flow is directed towards the deicing outlet and the ventilation outlet whilst the second air flow is directed towards the feet-level outlet; and an open position in which the first compartment and the second compartment communicate so that the first air flow and the second air flow can at least partly mix.
The aforementioned distribution means advantageously comprises a distribution shutter provided at the outlet from the second fan in order to control the second air flow.
This distribution shutter is preferably able to adopt a closed position in which the outlet of the second fan is closed and at least one open position in which the outlet of the second fan is open.
In another embodiment of the invention, the first fan is disposed on one side, or upstream side, of the radiator whilst the second fan is disposed on the other side, or downstream side of the radiator, and the deicing and ventilation outlet communicate with an outlet chamber situated on the downstream side, of the radiator, whilst the feet-level outlet communicates with a lower part of the casing on the upstream side of the radiator, so that the first air flow and second air flow pass through the radiator in opposite directions.
This embodiment makes it possible to dispose the first and second fan respectively upstream and downstream of the radiator.
In this embodiment, a distribution shutter is advantageously provided at the outlet of the second fan in order to control the second air flow and thus prevent mixing between the first air flow and second air flow.
Preferably, this distribution shutter is able to adopt at least two positions: a closed position in which the outlet of the second fan is closed and an open position in which the outlet of the second fan is open.
This distribution shutter is advantageously situated on the upstream side of the radiator.
In the aforementioned embodiment, provision can be made for the first fan and second fan to be situated adjacent to the casing.
Provision can also be made, as a variant, for the first fan to be situated adjacent to the casing whilst the second fan is situated at a distance from the casing, in particular close to the rear seats of the vehicle.
This last solution makes it possible to increase the compactness of the device and also to take off recirculated air at the rear of the passenger compartment.
In the invention, the first fan and second fan can be formed by two independent fans, or by a double fan.
The radiator of the device of the invention can be suitable for having a hot fluid pass through it under the control of a flow-rate adjustment valve, according to the technique known as xe2x80x9cadjustment on waterxe2x80x9d.
As a variant, the casing delimits an air heating branch in which the radiator is housed and a cold air transmission branch, and a mixing shutter is provided at the junction of the aforementioned two branches in order to ensure the distribution of the air flow between the two branches and to regulate the temperature of the air flow to be sent to the deicing and ventilation outlets. Thus the temperature is adjusted by means of the technique known as xe2x80x9cadjustment on airxe2x80x9d.
According to another characteristic of the invention, the device comprises an upper air passage provided in the casing close to the first part of the radiator and communicating with an outlet chamber downstream of the radiator, this upper air passage being controlled by a shutter so that a proportion of the first air flow can take the upper air passage without passing through the radiator. The shutter then makes it possible to mix the air in the upper part of the casing.
According to yet another characteristic of the invention, the device comprises a lower air passage provided in the casing close to the second part of the radiator and close to the feet-level outlet and communicating with an outlet chamber downstream of the radiator, this lower air passage being controlled by at least one shutter so that a proportion of the second air flow can take the upper air passage without passing through the radiator. The shutter then makes it possible to mix the air in the lower part of the casing.
In accordance with the invention, it is possible to use either a single radiator, or a radiator formed by the joining of two adjacent radiators able to have respectively the first air flow and the second air flow pass through them.
The invention also makes provision, in a variant, for an additional radiator situated opposite the second part of the radiator and also able to have the second air flow pass through it.
This makes it possible to increase the heating of the second air flow and, consequently, the heating of the lower part of the passenger compartment.
Other characteristics and advantages of the invention will emerge from a reading of the following detailed description, given solely by way of example, and with reference to the accompanying drawings.